This invention relates to charge transfer devices and, more particularly, to charge coupled devices (CCDs) for performing signal filtering.
The recent emergence of charge coupled technology has brought with it the advent of shift register and memory devices now well known in the art. In order to fabricate complete systems, other circuit functions are frequently utilized. By way of illustration, such supplementary functions often include logical AND and OR, binary counting, and signal filtering. Advantageously, if all of the circuits performing the various functions of the system are charge coupled devices, the manufacture of the system is simplified. A shift register and an AND gate, for example, could be fabricated on a single chip by well known integrated circuit technology. Moreover, interface problems, such as impedance matching and loading due to stray capacitance, would be alleviated.